ASIC Design and Implementation of Ten Gigabit Ethernet Transceiver

Abstract

The IEEE802.3 standard establishes a range of Ethernet speeds tailored for local area network applications. In this paper, we introduce an in-depth ASIC design for a ten gigabit Ethernet physical layer (PHY) over fiber, improving upon the existing 10Gb Ethernet XAUI interface through the use of 64/66b coding, as opposed to the traditional 8b/10b. Our focus is on the fundamental PHY transmitter (TX) and receiver (R <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$X$</tex>). Our proposed transceiver architecture is divided into two primary modules: the transmitter and the receiver. The transmitter handles packets from the MAC layer, converting them into a serial bit stream with a clock rate of 10.3125GB/s. Initially, it receives an XGMII signal, which is then encoded with 64b/66b coding and scrambled to achieve a DC-balanced line code with a suitable run length. Subsequently, the data is shifted to a different clock domain via a FIFO. The data undergoes serialization through a Gearbox for conversion. Within the receiving path, the serialized 10 Gb/s signal is deserialized. The data is then descrambled to pinpoint the 64b/66b frame boundary for data extraction. This refined data is shifted to a new clock domain using a FIFO, and its format resembles an XGMII interface at this point. Furthermore, the design integrates block synchronization, a test pattern generator/checker, and a Bit Error Rate (BER) monitor. The transceiver architecture is crafted using VHDL and synthesized for NCSU45nm CMOS technology utilizing FreePDK45 standard cells. For the final chip layout, EDA tools are leveraged for simulation, synthesis, physical implementation, and error validation. Specifically, Mentor Graphics - Modelsim - is chosen for HDL coding owing to its esteemed reputation in this domain. For synthesis, Synopsys - Design Vision - is employed to transform RTL to Gate-Level. Cadence tools, notably Soc Encounter for automated placement and routing, and Virtuoso for layout finalization, are also utilized. Our test chip registers a power consumption of 16.3454 mW from a 1.1 V supply.